Joint assembly with centering flange

ABSTRACT

A joint assembly for coupling first and second rotating parts, including a first joint member for mounting to the first rotating part, a second joint member including a centering flange having a first length disposed about an axis for mounting to the second rotating part, and at least one torque-transmitting element disposed between the first and second joint members for operatively coupling the first and second joint members. The centering flange has a contact section configured for being in a substantially interference fit with the second rotating part when mounting the centering flange to the second rotating part. The contact section has a second length substantially smaller than the first length of the centering flange such that the substantially interference fit between the centering flange and the second rotating part provides alignment between the centering flange and the second rotating part while minimizing forces necessary to mount the centering flange to the second rotating part.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending U.S. patent application Ser. No. 11/355,365, filed Feb. 16, 2006, which claims priority to and all the benefits of, and incorporates by reference, U.S. provisional patent application Ser. No. 60/654,323, filed Feb. 18, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to joint assemblies for operatively coupling rotating parts. More specifically, the present invention relates to joint assemblies comprising multiple joint members with one of the joint members having a centering flange for mounting to one of the rotating parts.

2. Description of Related Art

Joint assemblies for operatively coupling first and second rotating parts are well known in the art. One particularly well known joint assembly is that formed between one end of what is referred to as a constant velocity or CV joint that is included in the first rotating part, and the second rotating part. A typical CV joint of a first rotating part comprises a first CV joint member and a second CV joint member, the second CV joint member having an end adapted for mounting to a second rotating part as part of a joint assembly. A plurality of torque-transmitting elements, usually in the form of torque-transmitting balls, are disposed between the first and second CV joint members to operatively couple the first and second CV joint members. The first CV joint member can be fixed to other portions of the first rotating part in any number of fashions, such as by splined fits and the like. The second CV joint member often includes a centering flange for mating with the second rotating part.

Referring to FIG. 1, one such centering flange 10 is shown. Here, the centering flange 10 of second CV joint member 12 of the first rotating part has an overall length L₁. The centering flange 10 also has a contact section 14 configured for being in a substantially interference fit with an inner cylindrical surface 16 of the second rotating part 18. The contact section 14 has a second length L₂ that extends a substantial portion of the overall length L₁. Since the contact section 14 of second CV joint member 12 is in a substantially interference fit with the inner cylindrical surface 16 of the second rotating part 18, the volume of material in the contact section 14 must be displaced when mounting the centering flange 10 of second CV joint member 12 to the second rotating part 18, either by forces deflecting the centering flange 10 radially inwardly or by forces deforming the centering flange 10. The larger the volume of material to be displaced, the larger the force required to mount the centering flange 10 to the second rotating part 18, and likewise, the larger the force required to remove the centering flange 10 from the second rotating part 18 to repair or replace the joint assembly. Furthermore, this prior art centering flange, which is cylindrical so as to present a straight pilot, requires a precision fit and is susceptible to binding.

Therefore, there is a need in the art for a centering flange that has a contact section configured in a way such that the substantially interference fit between the centering flange and the second rotating part provides alignment between the centering flange and the second rotating part while minimizing the forces necessary to mount the centering flange to the second rotating part.

SUMMARY OF THE INVENTION AND ADVANTAGES

The present invention provides a joint assembly for operatively coupling first and second rotating parts. The first rotating part includes a CV joint that has a first CV joint member and a second CV joint member, the second CV joint member adapted for mounting to the second rotating part. At least one torque-transmitting element is disposed between the first and second CV joint members for operatively coupling the first and second CV joint members. The second CV joint member includes a centering flange disposed about an axis and having a first length for mounting to the second rotating part. The centering flange has a contact section configured for being in a substantially interference fit with the second rotating part when mounting the centering flange to the second rotating part. The contact section has a second length substantially smaller than the first length of the centering flange such that the substantially interference fit between the centering flange and the second rotating part provides alignment between the centering flange and the second rotating part while minimizing forces necessary to mount the centering flange to the second rotating part.

By making the length of the contact section substantially smaller than the overall length of the centering flange, the substantially interference fit requires displacement of less material than the prior art centering flange shown in FIG. 1 with the same outer dimensions. As a result, tolerances between the centering flange and the second rotating part can be increased. In other words, variations in dimensions of the centering flange of the present invention can be higher than the prior art centering flange since the contact section of the centering flange of the present invention is much smaller than that of the prior art centering flange.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a partial, cross-sectional, exploded view of a prior art joint assembly, showing its centering flange;

FIG. 2 is a cross-sectional, exploded view of a joint assembly of the present invention, showing its centering flange on a CV joint member;

FIG. 3 is an end view of the portion of the joint assembly of FIG. 2 that includes the CV joint of the first rotating part, with the cover enclosing the CV joint closed end removed;

FIGS. 4 and 5 respectively show a partial, cross-sectional, exploded view of the joint assembly having a first centering flange embodiment of the present invention, and an enlarged, partial, cross-sectional view of the first centering flange embodiment;

FIGS. 6-14 are enlarged, partial, cross-sectional views of various alternative embodiments of the centering flange of the joint assembly of the present invention; and

FIGS. 15 and 16 are enlarged, partial, cross-sectional views of the joint assembly of FIG. 2 showing it in different states of assembly.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a joint assembly for coupling first 20 and second 22 rotating parts is shown generally at 24. In one embodiment, the first rotating part 20 is described as including a constant velocity or CV joint. However, the joint assembly 24 may be any joint assembly capable of operatively coupling parts for rotation, while allowing the parts to deviate from perfect axial alignment with one another.

Referring to FIGS. 2-3, the first rotating part 20 includes a CV joint having a first CV joint member 26, known as an inner race in some embodiments and a second CV joint member 28, known as an outer race in some embodiments, that is mounted to the second rotating part 22, thereby forming joint assembly 24. As is typical of known CV joints, the first CV joint member 26 is formed with an outer curved surface 30 (see FIG. 3) in which a plurality of first ball grooves 32 are formed. The second CV joint member 28 has an open end 34 in which the first CV joint member 26 is disposed, an opposite end 36 closed by a cover, and an inner curved surface 38 in which a plurality of second ball grooves 40 are formed.

As is also typical of known CV joints, at least one torque-transmitting element 44 is disposed between the first 26 and second 28 CV joint members to operatively couple the first 26 and second 28 CV joint members. The at least one torque-transmitting element 44 is further defined as a plurality of torque-transmitting balls 44 arranged in pairs of the first 32 and second 40 ball grooves between the first 26 and second 28 CV joint members. A cage 46 contains and secures the plurality of balls 44 between the first 26 and second 28 CV joint members. The balls 44 transmit torque between the CV joint members 26, 28. The first 26 and second 28 CV joint members, the cage 46, and the balls 44 may be formed of any material capable of transferring torque between the first 20 and second 22 rotating parts including ferrous and non-ferrous metals, and the like.

Preferably, the first CV joint member 26 includes an opening 48 with splines for fitting onto mating splines of a stub shaft of the first rotating part 20. It should be appreciated by those skilled in the art that the stub shaft of the first rotating part 20 may, for example, form part of a drive shaft, with the joint assembly 24 being utilized to transmit rotational energy, e.g., torque, from the drive shaft to the second rotating part 22 wherein the second rotating part 22 may be an output shaft for extending to a transfer case, an input shaft of a differential, or the like.

A boot 54 is mounted onto the second CV joint member 28 and is arranged to be fitted onto the stub shaft of the first rotating part 20 to retain lubrication within the CV joint. The boot 54 may comprise any suitable material that is sufficiently flexible to allow the CV joint to operate through a wide range of angles, such as thermoplastic and elastomeric materials.

Referring to FIGS. 4, 15 and 16, the second CV joint member 28 of first rotating part 20 is formed with a radial mounting flange 56 adjacent the closed end 36. The radial mounting flange 56 is adapted to be bolted to a mating flange 58 of the second rotating part 22 in securing joint assembly 24 together. The mating flange 58 has a shoulder 62 with a cylindrical inner surface 64 of predetermined diameter centered about a second axis 66 of the second rotating part 22. Inner surface 64 defines a void in second rotating part 22.

The second CV joint member 28 of first rotating part 20 further includes an annular pilot projection or centering flange 68 disposed about an axis 70 of the second CV joint member 28 and extending axially toward the second rotating part 22. The centering flange 68 is received in the void defined by, and is dimensioned for a substantially interference fit with the cylindrical inner surface 64 in order to center the second CV joint member 28 of the first rotating part 20 on the second rotating part 22 during mounting with radial mounting flange 56 of the second CV joint member 28 and mating flange 58 of the second rotating part 22 positioned to be bolted together in securing joint assembly 24 together, after which axes 66, 70 are aligned. It should be appreciated that the substantially interference fit refers to the overall fit between the centering flange 68 and the cylindrical inner surface 64 while also including imperfections in the shapes of the centering flange 68 and the cylindrical inner surface 64 that may result in portions not being in an interference fit with one another. The centering flange 68 is preferably fixed to the second CV joint member 28 of first rotating part 20, and more preferably is integrally formed with the second CV joint member 28.

Referring to FIG. 5, the centering flange 68 is formed with a profiled outer surface 72 that enables the centering flange 68 to be slid into engagement with the cylindrical inner surface 64 of the shoulder 62 while the axes 66, 70 are misaligned (i.e., with the second CV joint member 28 of first rotating part 20 slightly cocked relative to the second rotating part 22, as shown in FIG. 15) without causing the second CV joint member 28 to bind at the centering flange 68 with the second rotating part 22 as one of a plurality of bolts is being tightened during a transition between a state of partial mounting or assembly wherein centering flange 68 and cylindrical inner surface 64 are interengaged and axes 66, 70 are misaligned, as shown in FIG. 15, and a state of more complete mounting or assembly wherein centering flange 68 and cylindrical inner surface 64 have a substantially interference fit and axes 66, 70 are aligned, as shown in FIG. 16. In one embodiment, shown in FIG. 5 for instance, the outer surface 72 of centering flange 68 is convexly curved in the axial direction in order to provide contact with the cylindrical inner surface 64 of the shoulder 62.

To better understand the fit between the centering flange 68 and the inner cylindrical surface 64 of the shoulder 62, the geometry and dimensioning of the centering flange 68 is now described. The centering flange 68 is disposed about the axis 70 of the second CV joint member 28 of the first rotating part 20 and has a first length L₁. The first length L₁ is considered the overall axial length of the centering flange 68 relative to the axis 70 of the second CV joint member 28.

The centering flange 68 has a contact section 76 configured for being in a substantially interference fit with the inner cylindrical surface 64 of the shoulder 62 of the mating flange 58 when mounting the centering flange 68 to the inner cylindrical surface 64. The contact section 76 has a second length L₂ substantially smaller than the first length L₁ of the centering flange 68 such that the substantially interference fit between the centering flange 68 and the inner cylindrical surface 64 provides alignment of the axes 66, 70 of the centering flange 68 and the second rotating part 22 while minimizing forces necessary to mount the centering flange 68 to the second rotating part 22.

In one embodiment, the term substantially smaller is further defined as the second length L₂ being less than 70 percent of the first length L₁. In a further embodiment, the term substantially smaller is further defined as the second length L₂ being less than 50 percent of the first length L₁. In yet another embodiment, the term substantially smaller is further defined as the second length L₂ being less than 30 percent of the first length L₁.

The centering flange 68 also includes at least one non-contact section 80 configured for not being in a substantially interference fit with the inner cylindrical surface 64 of the shoulder 62. The non-contact section 80 radially extends from the axis 70 of the second CV joint member 28 at a first maximum radius R₁ and the contact section 76 radially extends from the axis 70 at a second maximum radius R₂ greater than the first maximum radius R₁. As a result, the contact section 76 extends further radially outwardly than the non-contact section 80 to provide the substantially interference fit between the contact section 76 and the inner cylindrical surface 64.

The outer surface 72 may comprise any of a number of shapes in cross-sectional profile that will provide a contact section 76 for being in a substantially interference fit with the inner cylindrical surface 64 while minimizing the forces necessary to mount the centering flange 68 to the second rotating part 22 and accommodating misalignment during connection of the second CV joint member 28 of the first rotating part 20 with the second rotating part 22. In other words, various shapes of the outer surface 72 are contemplated by the present invention. Some of these shapes are shown in FIGS. 5-14. In FIGS. 6-14, the second length L₂ is respectively represented as L₃-L₁₁. Moreover, in the depicted embodiments the contact section reaches the second maximum radius R₂ only locally along its respective axial length L₂-L₁₁. Additionally, the numerals referring to like parts in FIGS. 6-14 have been respectively increased by increments of 100.

In FIGS. 5 and 6, the outer surface 72, 172 is further defined as a curved surface. The curved surface 72 of FIG. 5 is formed at a single radius R₃, while the curved surface 172 of FIG. 6 is formed at multiple radii R₄, R₅.

In FIGS. 7 and 8, the outer surface 272, 372 is further defined as a plurality of joined frustoconical surfaces. In FIG. 7, differing first and second frustoconical surfaces are arranged such that the bases of the first and second frustoconical surfaces are included in the contact section 276, while the second frustoconical surface also includes the non-contact section 280. In FIG. 8, the contact section 376 is partially defined at the intersection of two similar frustoconical surfaces.

In FIG. 9, the outer surface 472 is further defined as a semi-elliptical surface.

In FIG. 10, the outer surface 572 is further defined as a parabolic surface.

In FIG. 11, the outer surface 672 is further defined as a plurality of frustoconical surfaces joined by a cylindrical surface.

In FIG. 12, the outer surface 772 includes a projection or protrusion 78 extending radially outwardly relative to the axis 70 of the second joint member 728. The protrusion 78 includes the contact section 776, while the non-contact section 780 lies on both sides of the protrusion 78.

In FIG. 13, the outer surface 872 is further defined as a curved surface as in FIGS. 5 and 6, except that the curved surface is formed at a single radius R₆ with an offset. In this embodiment, the offset is in the non-contact section 880.

In FIG. 14, the outer surface 972 is further defined as a plurality of frustoconical surfaces joined by a curved surface.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims. 

1. A joint assembly for coupling first and second rotating parts, comprising: at least a portion of said first rotating part; said first rotating part portion including a centering flange having a first length disposed about an axis for mounting to the second rotating part, said centering flange having a non-contact section and an axially coextending contact section extending radially outward from said non-contact section, said contact section configured for being in a substantially interference fit with the second rotating part when mounting said centering flange to the second rotating part wherein said contact section has a second length substantially smaller than said first length of said centering flange, the mounting of said center flange to the second rotating part thereby being substantially devoid of binding engagement therebetween; alignment between said centering flange and the second rotating part provided by the substantially interference fit between said contact section and the second rotating part. 2-6. (canceled)
 7. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a curved surface.
 8. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a plurality of joined frustoconical surfaces.
 9. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a semi-elliptical surface.
 10. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a parabolic surface.
 11. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a plurality of frustoconical surfaces joined by a cylindrical surface in relation to said axis.
 12. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface includes a protrusion extending radially outwardly relative to said axis and that engages with the second rotating part.
 13. A joint assembly as set forth in claim 1, wherein said contact section has a radially outer surface that engages with the second rotating part and defined as a plurality of frustoconical surfaces joined by a curved surface. 14-19. (canceled)
 20. A joint assembly for coupling first and second rotating parts, comprising: a portion of said first rotating part including a first axis and a centering flange disposed about said first axis, said centering flange having a first length, said first length extending along the direction of said first axis; a portion of said second rotating part including a second axis and an inner surface disposed about and extending along the direction of said second axis, said inner surface defining a void in which said centering flange is received; said centering flange having a contact section extending radially outward relative to said first axis, said contact section having a second length, said second length extending along the direction of said first axis, said second length substantially smaller than said first length; said joint assembly having a first state in which said centering flange and said inner surface are engaged and said first and second axes are misaligned; said joint assembly having a second state in which said contact section and said inner surface have an substantially interference fit and said first and second axes are substantially aligned; a transition between said first and second states substantially devoid of binding between said first and second rotating parts.
 21. The joint assembly of claim 20, in which the alignment between said first and second axes is through said substantially interference fit between said contact section and said inner surface.
 22. The joint assembly of claim 20, wherein, in said first state, said contact section and said inner surface are engaged.
 23. A joint assembly through which first and second rotating parts are connected for the transmission of rotational energy therebetween, comprising: said first rotating part including a centering flange disposed about a first axis, said centering flange having a first length extending in the direction of said first axis; said centering flange including a non-contact section disposed about said first axis at a first radial distance from said first axis, and a contact section disposed about said first axis between said first radial distance and a second radial distance from said first axis, said second radial distance greater than said first radial distance, said contact section having a second length extending in the direction of said first axis, said second length substantially smaller than said first length; said second rotating part including an inner surface disposed about a second axis, said inner surface radially distanced from said second axis by a distance no less than said first radial distance, and no greater than said second radial distance; said centering flange disposed within said second rotating part between opposed sides of said inner surface, said first and second axes maintained substantially aligned through a substantially interference fit between said contact section and said inner surface.
 24. The joint assembly of claim 23, wherein said first length defines axially opposite ends of said centering flange, and said contact section is axially spaced from each said centering flange end.
 25. The joint assembly of claim 23, wherein said substantially interference fit is axially localized within said second length.
 26. The joint assembly of claim 23, wherein said inner surface defines a void in said second rotating part in which said centering flange is received, and with said centering flange at least partially received in said void during mounting of said first rotating part to said second rotating part, said non-contact section remains out of engagement with said inner surface.
 27. The joint assembly of claim 23, wherein said wherein said inner surface defines a void in said second rotating part in which said centering flange is received, and with said centering flange at least partially received in said void during mounting of said first rotating part to said second rotating part, said non-contact section remains out of engagement with said second rotating part.
 28. The joint assembly of claim 23, wherein only an axially localized portion of said contact section extends to said second radial distance.
 29. The joint assembly of claim 23, wherein said inner surface defines a void in which said centering flange is received; said joint assembly having a first state of partial assembly in which said centering flange and said inner surface are engaged and said first and second axes are misaligned; said joint assembly having a second state of more complete assembly in which said contact section and said inner surface have said substantially interference fit and said first and second axes are substantially aligned; and the transition between said first and second states is substantially devoid of binding between said first and second rotating parts.
 30. The joint assembly of claim 29, wherein in said first state said contact section and said inner surface are engaged.
 31. The joint assembly of claim 23, wherein said contact section has an outer surface defined as one of a curved surface, a frustoconical surface, a pair of joined frustoconical surfaces, a semi-elliptical surface, a parabolic surface, a plurality of frustoconical surfaces joined by a cylindrical surface, including a protrusion extending radially outward, and a plurality of frustoconical surfaces joined by a curved surface. 